Accounts Receivable - Accounts Receivable Balance (Details) - USD ($)  | 
Apr. 30, 2020  | 
Apr. 30, 2019  | 
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| Receivables [Abstract] | Ìý | Ìý | 
| Accounts receivable | $ 22,786,847 | $ 14,988,744 | 
| Long term contractual accounts receivable | (6,701,136) | (3,085,243) | 
| Less: Allowance for doubtful accounts | (1,758,920) | (1,247,031) | 
| Accounts receivable, net | $ 14,326,791 | $ 10,656,470 | 
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- Definition Current portion of long term contractual receivable. No definition available. 
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- Definition Amount, before allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Amount of allowance for credit loss on accounts receivable, classified as current. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- References No definition available. 
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